Objective. Describes the prevalence and severity of dental caries in Colombian preschool children with primary dentition. Methods. Cross-sectional study, using a random sample by clusters of 336 children between 3 and 5 years of age, examined during 2010. Dental caries lesion detection was carried out by visual criteria (ICDAS). A questionnaire was answered by the parents. Examiner´s calibration in ICDAS assessment method was carried out with a benchmark examiner, and the inter-examiner and intra-examiner reliability was calculated. The association exploration was analyzed parting from the prevalence ratio (PR; 95 percent confidence interval CI). The multivariate analysis was done using poisson regression model, obtaining adjusted values by age and gender. Results. Dental caries prevalence was 88.9 %, (51.4 % for experience and 37.5 % for non cavitated lesions). The average dmf-t was 1.7 +/-2.5. The most commonly present lesions were non cavitated, being the smooth surfaces in cervical area the most affected. For caries experience there was significance with a cariogenic diet, tooth brushing parent supervision and the use of a high fluoride content toothpaste, while the severity of dental caries was associated with dental consultations per year, mother´s schooling and school behavior. Conclusions. The dental caries prevalence and severity was associated with different risk factors ( weekly cariogenic diet consumption, no parental tooth brushing supervision, use of high fluoride content toothpaste, visit to the dentist less than one/year, mother schooling less than high school and inadequate school behavior) , which at this age can be oriented by parents through a change in behavior.